Add a change note for A20-8-1/MEM56-CPP/A18-1-4.

change_notes/2023-08-02-a8-4-13-false-positives.md

@@ -1 +1,2 @@
- - `A8-4-13` - reduce false positives when using gcc/clang where a modifying operation was used on a shared_ptr.
+ - `A8-4-13`
+  - Address false positives caused by missing modelling of modifying operations for smart pointers for some standard libraries (such as libstdc++).

change_notes/2023-08-02-smart-pointers.md

@@ -0,0 +1,5 @@
+ - `A20-8-1`/`MEM56-CPP`
+    - Address false negatives caused by lack of modelling of flow through smart pointers.
+    - Reduce flow paths through standard library headers to simplify results.
+ - `A18-1-4`
+    - Address false positives caused by missing modelling of modifying operations for smart pointers for some standard libraries (such as libstdc++).